Apparatus for treating coated paper and the like



May 15, 1934.

H. F. sco'rT 1,958,721 APPARATUS FOR TREATING COATED PAPER AND THE LIKEFiled Sept. ll. 1930 Patented May 15, 1934 UNITED STATES APPARATUS FORTREATING COATED PAPER AND THE LIKE Henry F. Scott, Framingham, Mass.,assigner to Dennison Manufacturing Company, Framingham, Mass., acorporation of Massachusetts Application september 11, 1930, serial No.481,123

4 claims. (c1. :a1-1s) in the manufacture of coated paper and the like,such as gummed paper and other sheet material coated with induratedcomposition, it

is usually necessaryto produce a network of I cracks in the coatingafter it hardens to reduce its curling tendency. Heretofore, this hasusually been accomplished by drawing the paper over a series ofknife-edges at a pronounced angle and under heavy tension. Thisprocedure has been',` unsatisfactory for many reasons chief of which arethe following. Inasmuch as the knife-edges incline from end to end inopposite l directions at approximately forty-five degrees to the path ofthe paper, breaker machines for wide bands o f paper involve high firstcost and require extensive floor space. Inasmuch as the knife-edgesrequire frequent sharpening the' maintenance cost is considerable. Thepaper is subjected to relatively highl tension and considerable power isrequired to draw the paper over the sharp edges. 'Ihere is great dangerof the paper tearing as it passes over the edges and when it does tearthe machine must be shut down for rethreading. At each end of a roll ofpaper and on each side of a rupture,

the machine fails to break the coating throughout a. lengthapproximately equal to the length of the machine, thus resulting inlarge percentages of waste. The knife-edges ltend to roughen theuncoated surfaces of the paper against which they rub, necessitating arecalendering operation; they also introduce a. reverse curl, commonlycalled reverse, which ordinarily requires the paper to be drawn over oneor more auxiliary edges bearing against the coated side.

The only practical way of regulating the noncurling effect of theknife-edges on the paper, especially while the machine is in operation,is to vary the tension on the paper. Practically such machines areapplicable only to stock in roll form in contradistinction to stock insheet form.

Objects of the present invention are to avoid the aforesaiddisadvantages and to provide a method and machine which involves muchlower first cost, which requires far less floor space, which incurssmall maintenance cost, which requires little or no tension on the paperand less power, which is much easier to thread and 1ess likely to tear'the paper, which @involves substantially no waste at the ends of eachpiece of paper, which unlike a knife-edge has substantially lno tendencyto loosen',l the surface fibers of the paper and therefore does' notnecesl 155 sitate recalenderin'g, which has: comparatively littlereverse curl and that only longitudinally of the paper so that it may ifdesired be removed by a single cross-bar extending transversely of themachine so as not to add materially to the length of the machine, whichmay be readily 6 0 and accurately adjusted to regulate the noncurlingeffect without stopping the machine, Wfhich is adapted for use on eitherroll or sheet stock, which will break stock having higher moisturecontent, thus requiring less 65 time and heat in preparing the stock forthe breaking operation, which can be incorporated in the coating and/orcalendering machine, thereby reducing the number of separate operations,and which is generally superior to prior methods and machines for thepurpose.

In one aspect the present invention involves producing in the paper orother sheet material a row of juxtaposed waves of small extent in bothlength and width and advancing the waves along the paper transversely oftherow, thereby to flatten and/or soften the paper. The effect on' thepaper may be regulated in degree by varying the depth of the waves. Apreferred method of producing the waves consists in simultaneously`flexing the paper in two dimensions by producing in the back of thepaper a series of juxtaposed indentations of small extent in both ofsaid dimensions and concomitantly producing relative movement of thepaper edgewise thereof, that is moving the paper relatively to theindenting means and/or vice versa, to cause the indentations to tracecontinuous juxtaposed paths, preferably parallel paths. While the paperis treated as aforesaid it is preferably supported on its coated side bya soft support such as a layer of moderately soft rubber, either in theform of a covering on a drum or a belt sliding over a table, the paper'being indented into the softsupport by surfaces curved in two dimensions`and the aforesaid waves therefore being produced in the softsupport asWell as in the paper. Said curved surfaces are preferably rolling`surfaces so as to avoid abrasion, reduce wear, and minimize the powerrequired. While these rollers may be integrally interconnected in theform of circumferential corrugations on a small drum or shaft, thecorrugations being leither circular or wavy circumferentially of theaxis, they iare preferably in the form of separate balls. The convexsurfaces are preferably arranged in a row (straight, curved orstaggered) in which case the aforesaid relative movement is eitherperpendicular or oblique or otherwise transverse of the row. By using aplurality of rows and staggering the indenting surfaces of successiverows, all portions of the paper may be thoroughly flexed without making.the balls or the like excessively small.

For the purpose of illustrations three typical embodiments of theinvention are shown in the accompanying drawing in which;

Fig. 1 is a side elevation of one embodiment, largely diagrammatic butshowing parts in section;

Fig. 2 is a section on line 2-2 of Fig. 1;

Fig. 3 is a bottom plan viewed from the line 3-3 of Fig. 2;

Fig. 4 is a side elevation of another embodiment, showing parts insection;

Fig. 5 is an enlarged top plan of parts of Fig.

, 4; 'and Fig. 6 is a side elevation of still another embodiment,showing parts in section.

The particular embodiment of the invention illustrated in Figs-1, 2 and3 comprises an endless belt 1 movable in the direction of the arrow byrevolving drums 2 and 3, a stationary table 4 to support the upperstretch of the belt, a takeup reel 5 to receive the `gummed paper 6 orthe like after it is broken, idler rolls 7 and 8 for holding the paper 6in frictional engagement with. the belt l, and disks 9 havingdown-turned rims 10 for confining groups of balls 1l which may beordinary steel balls such as commonly used in bearings. The disks 9 arerotated about central axes by means of shafts 12, thereby to cause theballs 11 to roll over the paper as the paper feeds through the machinein the direction of the arrow. If desired, the lower faces of the disks9 may be unpolished to increase the friction between the disks and theballs thereby to increase the rotational tendency imparted to the ballsby the rotating disks. if the axes of the shafts 12 are xed the disksare provided in sufficient number and in such locations as to roll thepaper 6 throughout its entire width. However in some cases it ispreferable to move the shafts 12 transversely of the papier, either in astraight line or along arcs of circles, as they are being rotated abouttheir own axes, thereby to roll the entire surface of the paper with alesser number of disks.

While the operation oi this particular embodiment of the invention willbe evident from the above description or the generic invention,l

it may be .noted that the paper'moves at the same linear velocity as thebelt l and that the balls indent the paper into the soit surface of thebelt sufficiently to produce a ne network of cracks throughout the gumor other hardened coating on the paper, the coated surface oi the paperpreferably being directed toward the belt instead of toward the balls.The pressure on the balls depends upon a number of factors' but inbreaking ordinary gummed paper with balls onequarter inch in diameterthe rubber belt pref-- erably has sulcent give to require approximatelyone-half pound pressure per ball. Theonly substantial tension or pull towhich the paper need be subjected is the small amount exerted by thetake-up roll 5 which is required to remove the small amount of reverseby drawing the paper over the blade 13.

The embodiment illustrated in Figs. l and 5 is similar to that shown inFigs. l to 3 except that the balls l1 are arranged in rows transverselyof the paper, are retained in position by slotted plates la and are'pressed against the weaver paper by freely rotatable cylinders .l5resting upon the balls. The pressure of the balls upon the paper may bedetermined either by predetermining the weight of the cylinders 15 oradjustable springs may be associated with the cylinders 15. As shown inthe plan view of Fig. 3 the balls of each two rows are not onlystaggered with relation to each other but with relation to the balls ofthe other two rows so that the balls of the four rows trace paths alongthe paper, the center lines of which are spaced apart only one-fourththe diameter of each ball.

The third embodiment chosen for the purpose of illustration comprises aflexible belt 16 trained over guide rolls 17 with sufficient slack toform a depending loop between the two upper rolls, feed and take-uprolls 18 and 19 for feeding the paper or the like through the machine, aplurality of rows of balls 20 resting on the paper in the dependingloop, stationary guides 21 surrounding the group of balls for holdingthem in position and a revolving cylinder22 for pressing the ballsagainst the paper. While the cylinder 22 may be positively driven at aperipheral velocity equal to the linear velocity of the belt i6, it ispreferably driven solely through the medium of the balls which in turnare driven by frictional engagement with the paper.

-It should be understood that the present disclosure is for the purposeof illustration only and that this invention includes all modificationsand equivalents which fall within the scope of the appended claims.

I claim:

l. Apparatus for treating paper and the like comprising a plurality ofrows of surfaces convex both longitudinally and transversely of therows, and means for producing relative movement of the paper and saidsurfacesedgewise of the paper and transversely of the rows while thepaper is indented by said surfaces, the surfaces of successive rowsbeing staggered with respect to the direction of said relative movement.

2. Apparatus fortreating paper and the like comprising a plurality ofrows of rollers rotat1 able about axes extending longitudinally of therows, the periphery of each. roller being convex longitudinally of therows, and means for producing relative movement of the paper and rollersedgewise of the paper transversely 4of the rows, while the paper isindented by the rollers,

the rollers of successivev rows being 'staggered with respect to thedirection ofy relative movement.

3. Apparatusfor treating paper and the like comprising a-plurality ofrows'of balls rotatable about axes extending longitudinallyof the rows,

and means for producing relative movement of paper, the balls beingclosely'arranged in a group L extending both transverselyfan'dlongitudinally paper while the'paper isi indented bytheA balls,

` of v`the 'papen-'and means -vfor producing vrelative A 'movement ofthel paperand-'balls parallel to the successive balls being-staggeredfwith respect to

